Textile materials in which a backing of fibrous material is combined with a warp-knitted superposed structure are well known. In one type of material the loose fibers which form the body of the backing are traversed by the loop chains of a fringe-stitched yarn system. In another type of material the warp threads are tied in with the fiber backing by tricot stitches or by another yarn system available for the production of warp-knitted webs.
It is a common disadvantage of these and similar textile materials that they are not run-resistant: that is, they develop more or less readily visible "ladders" when a single stitch is broken. Such "ladders" which extend in the lengthwise direction of the material are particularly conspicuous when the structure is made of silk threads.
One attempt to lessen or to eliminate the development of "ladders" in textile materials involves the application of chemical bonding agents which is very expensive. Another attempt which also requires considerable additional expenditure, seeks to combine several yarn systems in the warp knitting process, but this method does not always succeed in making the material run-resistant. Yet another approach is to embed the loose fibers in the loops of the chain stitched warp threads without interlacing them therewith. For this purpose the needle shanks are provided with hook-like grooves in which the loose fibers are caught. As the needles are moved back, the fibers are dragged along and subsequently .[.knitting.]. .Iadd.knitted .Iaddend.stitches are formed on top of the fibers. However, this process very rarely provides an adequate deposition of fibers in the loops of warp threads: as the fabricated material is transferred, the perforations made by the needles in the fibrous backing layer during the stitching operation becomes enlarged, so that the surrounding loose fibers are pushed aside. During the subsequent needle passes there will be only a very few fibers in the operating range of the grooved needles. Moreover, the face of a material wherein loose fibers are inserted in the loops of warp threads, without being interlaced therewith, has in general an uneven appearance and even resembles, in places, a pile fabric such as plush, which is undesirable for a number of purposes. Also, the work that has to be done by the grooved needles in pulling fibers out of the backing and dragging them along, is apt to add substantially to the total of the forces normally acting upon the needles. Since grooved needles are not very strong they tend to break under the stresses. Even if an effort were made to supply the grooved needles with a constant quantity of loose fibers, this would not lead to a satisfactory solution of the problems, since neither the appearance of the material nor the functioning of the machine equipped with conventional type needles would be improved.